by Kristina Lewis, MD
In the trial just published in NEJM, the investigators studied 3,731 non-diabetic patients with obesity, 2/3 of whom received liraglutide and 1/3 of whom received a placebo. Both groups got diet and exercise advice to promote weight loss. At the end of the study, participants in the liraglutide group lost significantly more weight than those getting placebo (8.4kg vs 2.8kg, on average), and well over half of the liraglutide recipients (63%) had lost more than 5% of their body weight, a clinically-significant endpoint with proven impacts for metabolic health, including diabetes prevention.
Although these results bolster the FDA’s decision to allow liraglutide’s use for the indication of weight loss, the cost for this particular medication must be considered. When used for weight loss, the drug (now marketed under the trade name Saxenda) costs somewhere in the neighborhood of $1,000 for a 30-day supply. For most Americans, this exorbitant price will prohibit long-term use of liraglutide, probably significantly limiting its impact on health.
As is often the case with drug trials, this study was funded by Novo-Nordisk, the manufacturer of Victoza/Saxenda. While the weight loss results are impressive from a clinical standpoint, I can’t help but wonder what they would have looked like if those patients had faced the full out-of-pocket costs of the medicine. Even with liraglutide provided free-of-charge (i.e. without any risk of side effects to peoples’ bank accounts), the difference in weight loss between the 2 groups was moderate, but not mind-blowing. I’m betting it would have been smaller in an intention-to-treat study where patients were paying for the medications themselves.
Before recommending this medication to patients, I would like to have a few questions answered. Is losing 5% of your body weight over a year worth $12,000? How does Saxenda compare to intensive lifestyle interventions in terms of cost-effectiveness? How does it stack up against other slightly cheaper drugs already approved for long-term use, like Qsymia and Belviq? These and other questions will be critical to answer in follow-up comparative effectiveness studies, so that policy makers, clinicians and patients can make informed decisions about the best treatment options for obesity.